From bf6ce6b07b4896f403b9def23ccd58268c980629 Mon Sep 17 00:00:00 2001
From: Daniel Neilson <dneilson@azul.com>
Date: Tue, 18 Jul 2017 01:06:52 +0000
Subject: [PATCH] Add element-atomic mem intrinsic canary tests for Dataflow
 Sanitizer.

Summary:
Add canary tests to verify that DFSAN currently does nothing with the element atomic memory intrinsics for memcpy, memmove, and memset.

Placeholder tests that will fail once @llvm.mem[cpy|move|set] instrinsics have been added to the MemIntrinsic class hierarchy. These will act as a reminder to verify that DFSAN handles these intrinsics properly once they have been added to that class hierarchy.

Note that there could be some trickiness with these element-atomic intrinsics for the dataflow sanitizer in racy multithreaded programs. The data flow sanitizer inserts additional lib calls to mirror the memory intrinsic's action, so it is possible (very likely, even) that the dfsan buffers will not be in sync with the original buffers. Furthermore, implementation of the dfsan buffer updates for the element atomic intrinsics will have to also use unordered atomic instructions. If we can assume that dfsan is never run on racy multithreaded programs, then the element atomic memory intrinsics can pretty much be treated the same as the regular memory intrinsics.

Reviewers: reames

Reviewed By: reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D35507

llvm-svn: 308249
---
 .../unordered_atomic_mem_intrins.ll           | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 test/Instrumentation/DataFlowSanitizer/unordered_atomic_mem_intrins.ll

diff --git a/test/Instrumentation/DataFlowSanitizer/unordered_atomic_mem_intrins.ll b/test/Instrumentation/DataFlowSanitizer/unordered_atomic_mem_intrins.ll
new file mode 100644
index 00000000000..9b6e3db9050
--- /dev/null
+++ b/test/Instrumentation/DataFlowSanitizer/unordered_atomic_mem_intrins.ll
@@ -0,0 +1,37 @@
+; RUN: opt < %s -dfsan -dfsan-args-abi -S | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+;; Placeholder tests that will fail once element atomic @llvm.mem[move|set] instrinsics have
+;; been added to the MemIntrinsic class hierarchy. These will act as a reminder to
+;; verify that dfsan handles these intrinsics properly once they have been
+;; added to that class hierarchy.
+
+declare void @llvm.memset.element.unordered.atomic.p0i8.i64(i8* nocapture writeonly, i8, i64, i32) nounwind
+declare void @llvm.memmove.element.unordered.atomic.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32) nounwind
+declare void @llvm.memcpy.element.unordered.atomic.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32) nounwind
+
+define void @test_memcpy(i8* nocapture, i8* nocapture) {
+  ; CHECK-LABEL: dfs$test_memcpy
+  ; CHECK: call void @llvm.memcpy.element.unordered.atomic.p0i8.p0i8.i64(i8* align 1 %0, i8* align 1 %1, i64 16, i32 1)
+  ; CHECK: ret void
+  call void @llvm.memcpy.element.unordered.atomic.p0i8.p0i8.i64(i8* align 1 %0, i8* align 1 %1, i64 16, i32 1)
+  ret void
+}
+
+define void @test_memmove(i8* nocapture, i8* nocapture) {
+  ; CHECK-LABEL: dfs$test_memmove
+  ; CHECK: call void @llvm.memmove.element.unordered.atomic.p0i8.p0i8.i64(i8* align 1 %0, i8* align 1 %1, i64 16, i32 1)
+  ; CHECK: ret void
+  call void @llvm.memmove.element.unordered.atomic.p0i8.p0i8.i64(i8* align 1 %0, i8* align 1 %1, i64 16, i32 1)
+  ret void
+}
+
+define void @test_memset(i8* nocapture) {
+  ; CHECK-LABEL: dfs$test_memset
+  ; CHECK: call void @llvm.memset.element.unordered.atomic.p0i8.i64(i8* align 1 %0, i8 88, i64 16, i32 1)
+  ; CHECK: ret void
+  call void @llvm.memset.element.unordered.atomic.p0i8.i64(i8* align 1 %0, i8 88, i64 16, i32 1)
+  ret void
+}